Hemolytic disease of the fetus and newborn.

KM The primary cause, of course, is maternal antibodies to red blood cells. Their formation usually occurs at delivery, and in the following pregnancy, those antibodies cross through the placenta and can affect the next fetus. When the antibodies attach to the fetal red blood cells, the cells break down and the fetus becomes anemic. In the United States, the 3 antibodies that cause nearly all the problems in utero are anti-D, anti-Kell, and anti-c. There are approximately 40 more antibodies, including Lutheran and Duffy, that have been reported to cause hemolytic disease of the newborn. This type of disease does not require treatment in utero, however—it is usually limited to problems like jaundice. I have only needed to perform an intrauterine transfusion in 1 patient with antiDuffy antibody. When hemolytic disease of the newborn was first recognized in the 1950s and 1960s, we saw the condition only after the baby was born, so the name made sense. But now that we can detect and treat the disease in utero, I have proposed that we refer to the condition as hemolytic disease of the fetus and newborn.